structured data stored in a history collection where parts of the structure are used to uniquely identify the data within the data collection

Note 1 to entry: Most historical data applications assume only one current value per timestamp. Therefore, the timestamp of the data is considered the unique identifier for that value. Some data or meta data such as Annotations may permit multiple values to exist at a single timestamp. In such cases the Server would use one or more parameters of the StructuredHistoryData entry to uniquely identify each element within the history collection. Annotations are examples of StructuredHistoryData.